Vinyl chloride resin composition, vinyl chloride resin molded product, and laminate

ABSTRACT

Provided is a vinyl chloride resin composition that can provide a molded product having superior flexibility at low temperatures. The vinyl chloride resin composition includes (a) a vinyl chloride resin and (b) a diester plasticizer formed from a compound represented by formula (1) shown below. In formula (1), R 1  and R 3  are monovalent hydrocarbon groups that may be the same or different and R 2  is a divalent hydrocarbon group. Moreover, (a) the vinyl chloride resin includes (x) a base vinyl chloride resin in an amount of from 70 mass % to 100 mass % and (y) vinyl chloride resin fine particles in an amount of from 0 mass % to 30 mass %.

TECHNICAL FIELD

The present disclosure relates to a vinyl chloride resin compositionthat can provide a powder molded product having superior flexibility atlow temperatures, a vinyl chloride resin molded product formed throughpowder molding of the vinyl chloride resin composition, and a laminateincluding the vinyl chloride resin molded product and a foamedpolyurethane molded product.

BACKGROUND

An automobile instrument panel has a structure in which a foamedpolyurethane layer is disposed between a substrate and a surface skinformed from a vinyl chloride resin. Over time, the surface skin formedfrom the vinyl chloride resin discolors and experiences a reduction inheat aging resistance. One main cause of discoloration and so forth ofthe surface skin is a chemical reaction that occurs as a result of atertiary amine used as a catalyst in formation of the foamedpolyurethane layer migrating to the surface skin formed from the vinylchloride resin. In order to prevent surface skin discoloring, a urethaneintegrated foamed molded product has been considered in which a granularcatcher agent that captures volatile organic compounds produced in afoamed polyurethane layer and that is coated with an open cell foamsheet is provided near locations at which the edges of the foamedpolyurethane layer are sealed by a surface skin and a substrate (forexample, refer to PTL 1). However, there are sections where the surfaceskin and the foamed polyurethane layer are in contact in this urethaneintegrated foamed molded product and, as a result, surface skindiscoloration due to the aforementioned chemical reaction cannot beprevented over a long period and heat aging resistance of the surfaceskin decreases.

On the other hand, a laminate has been considered in which a syntheticresin foamed layer is provided that joins a core material and a surfaceskin and in which the core material includes gas release holes forreleasing gas produced in the foamed layer (for example, refer to PTL2). However, the synthetic resin foamed layer and the surface skin arein contact in this laminate and, as a result, surface skin discolorationdue to the aforementioned chemical reaction cannot be prevented over along period and heat aging resistance of the surface skin decreases.

Furthermore, a molded product has been considered that includes apolyurethane molded product, a surface skin containing a vinyl chlorideresin that covers at least one surface of the polyurethane moldedproduct, and an amine catcher layer disposed between the polyurethanemolded product and the surface skin (for example, refer to PTL 3).However, it is not possible to prevent migration of a tertiary amine tothe surface skin formed from the vinyl chloride resin over a long perioddue to volatility of the amine catcher. Therefore, surface skindiscoloration due to the aforementioned chemical reaction cannot beprevented over a long period and heat aging resistance of the surfaceskin decreases in this molded product.

On the other hand, a vinyl chloride resin composition for powder moldingthat includes a prescribed trimellitate plasticizer has been consideredas a raw material for a surface skin of an automobile interior material(for example, refer to PTL 4). However, it is necessary to increase theblended amount of the plasticizer in order to improve heat agingresistance of a surface skin material that is obtained through powdermolding of the vinyl chloride resin composition, which results in thesurface skin material feeling sticky due to the plasticizer. A vinylchloride resin composition for powder molding has also been consideredthat includes 100 parts by mass of vinyl chloride resin particles madefrom a vinyl chloride resin having an average degree of polymerizationof at least 1,500 and 110 parts by mass to 150 parts by mass of aprescribed trimellitate plasticizer (for example, refer to PTL 5).

CITATION LIST Patent Literature

PTL 1: JP 2007-216506 A

PTL 2: JP H8-90697 A

PTL 3: JP H4-26303 B

PTL 4: JP H2-138355 A

PTL 5: WO 2009/107463

SUMMARY Technical Problem

In order that fragments of a surface skin of an automobile instrumentpanel that is laminated with a foamed polyurethane layer are notscattered when the surface skin breaks as designed at low temperaturesupon expansion of an air bag, there has been demand in recent years foran automobile instrument panel including a surface skin having superiorflexibility at low temperatures. However, is has not been possible toachieve an automobile instrument panel including a surface skin such asdescribed above.

The present disclosure aims to solve a problem of provision of a vinylchloride resin composition that can provide a molded product havingsuperior flexibility at low temperatures. Another problem that thepresent disclosure aims to solve is provision of a vinyl chloride resinmolded product that is formed through powder molding of the vinylchloride resin composition described above and that has superiorflexibility at low temperatures, and provision of a laminate includingthe vinyl chloride resin molded product and a foamed polyurethane moldedproduct.

Solution to Problem

As a result of conducting diligent investigation in order to solve theproblems described above, the present inventors discovered that a vinylchloride resin composition including (a) a vinyl chloride resin and (b)a diester plasticizer formed from a prescribed compound can provide amolded product having particularly superior flexibility at lowtemperatures. This discovery leads to the present disclosure.

A presently disclosed vinyl chloride resin composition includes (a) avinyl chloride resin and (b) a diester plasticizer formed from acompound represented by formula (1) shown below.

In formula (1), R¹ and R³ are monovalent hydrocarbon groups that may bethe same or different and R² is a divalent hydrocarbon group. Also, (a)the vinyl chloride resin includes (x) a base vinyl chloride resin in anamount of from 70 mass % to 100 mass % and (y) vinyl chloride resin fineparticles in an amount of from 0 mass % to 30 mass %.

The presently disclosed vinyl chloride resin composition preferablyincludes from 5 parts by mass to 200 parts by mass of (b) the diesterplasticizer relative to 100 parts by mass of (a) the vinyl chlorideresin.

The presently disclosed vinyl chloride resin composition may furtherinclude (c) a trimellitate plasticizer.

The presently disclosed vinyl chloride resin composition preferablyincludes a total amount of from 5 parts by mass to 200 parts by mass of(b) the diester plasticizer and (c) the trimellitate plasticizerrelative to 100 parts by mass of (a) the vinyl chloride resin.

The presently disclosed vinyl chloride resin composition preferably hasa blending ratio of (b) the diester plasticizer relative to (c) thetrimellitate plasticizer (diester plasticizer/trimellitate plasticizer),expressed as a mass ratio, of from 1/99 to 99/1.

Moreover, in formula (1), R¹ and R³ are preferably monovalent aliphatichydrocarbon groups having a carbon number of 2-24 that may be the sameor different and R² is preferably a divalent aliphatic hydrocarbon grouphaving a carbon number of 1-14.

R¹-R³ in formula (1) preferably each have a straight chain ratio of atleast 90 mol %.

In the presently disclosed vinyl chloride resin composition, (x) thebase vinyl chloride resin is preferably vinyl chloride resin particles.

The presently disclosed vinyl chloride resin composition is preferablyused for powder molding and is more preferably used for powder slushmolding.

A presently disclosed vinyl chloride resin molded product is obtainablethrough powder molding of the vinyl chloride resin composition describedabove.

The vinyl chloride resin molded product is preferably used as a surfaceskin of an automobile instrument panel.

A presently disclosed laminate includes a foamed polyurethane moldedproduct and the vinyl chloride resin molded product described above. Thelaminate is preferably used as a laminate of an automobile instrumentpanel.

Advantageous Effect

The presently disclosed vinyl chloride resin composition can provide amolded product having superior flexibility at low temperatures.

DETAILED DESCRIPTION

(Vinyl Chloride Resin Composition)

A presently disclosed vinyl chloride resin composition includes (a) avinyl chloride resin and (b) a diester plasticizer formed from aprescribed compound, and may optionally further include (c) atrimellitate plasticizer, additives, and so forth.

<Vinyl Chloride Resin>

Examples of (a) the vinyl chloride resin include homopolymers of vinylchloride and copolymers preferably including at least 50 mass % of vinylchloride units and more preferably at least 70 mass % of vinyl chlorideunits. Specific examples of comonomers of vinyl chloride copolymersinclude: olefins such as ethylene and propylene; halogenated olefinssuch as allyl chloride, vinylidene chloride, vinyl fluoride, andtrifluorochloroethylene; carboxylic acid vinyl esters such as vinylacetate and vinyl propionate; vinyl ethers such as isobutyl vinyl etherand cetyl vinyl ether; allyl ethers such as allyl-3-chloro-2-oxy propylether and allyl glycidyl ether; unsaturated carboxylic acids, esters ofunsaturated carboxylic acids, and acid anhydrides of unsaturatedcarboxylic acids such as acrylic acid, maleic acid, itaconic acid,acrylic acid-2-hydroxyethyl, methyl methacrylate, monomethyl maleate,diethyl maleate, and maleic anhydride; unsaturated nitriles such asacrylonitrile and methacrylonitrile; acrylamides such as acrylamide,N-methylolacrylamide, acrylamido-2-methylpropane sulfonic acid, and(meth)acrylamidopropyltrimethylammonium chloride; and allyl amines andderivatives thereof such as allylamine benzoate anddiallyldimethylammonium chloride. The above examples of monomers aremerely some of the monomers (comonomers) that are copolymerizable withvinyl chloride. Further examples of various types of monomers that canbe used as comonomers are provided in pages 75-104 of “Polyvinylchloride” edited by the Vinyl Section of the Kinki Chemical SocietyJapan and published by Nikkan Kogyo Shimbun, Ltd. (1988). Any one ofthese monomers or any two or more of these monomers may be used.Moreover, (a) the vinyl chloride resin may include a resin formed bygraft polymerization of (1) vinyl chloride or (2) vinyl chloride and acopolymerizable comonomer such as described above with a resin such asan ethylene-vinyl acetate copolymer, an ethylene-methyl methacrylatecopolymer, an ethylene-ethyl acrylate copolymer, or a chlorinatedpolyethylene.

The present description uses the term “(meth)acryl” to refer to eitheror both of acryl and methacryl.

Conventionally known production methods such as suspensionpolymerization, emulsion polymerization, solution polymerization, andbulk polymerization can be used to produce (a) the vinyl chloride resin.

Furthermore, (a) the vinyl chloride resin may be a single type of vinylchloride resin or a mixture of two or more types of vinyl chlorideresins. Specifically, (a) the vinyl chloride resin may be (x) a basevinyl chloride resin only or may be a mixture of (x) a base vinylchloride resin and (y) vinyl chloride resin fine particles. It ispreferable that (a) the vinyl chloride resin includes (x) a base vinylchloride resin in an amount of from 70 mass % to 100 mass % and (y)vinyl chloride resin fine particles in an amount of from 0 mass % to 30mass %.

In the vinyl chloride resin composition, (x) the base vinyl chlorideresin included in (a) the vinyl chloride resin functions as a matrixresin. Moreover, (y) the vinyl chloride resin fine particles, which areoptionally included in (a) the vinyl chloride resin as desired, functionas a dusting agent (powder fluidity modifier) described further below.It is preferable that (x) the base vinyl chloride resin is produced bysuspension polymerization and (y) the vinyl chloride resin fineparticles are produced by emulsion polymerization.

[Base Vinyl Chloride Resin]

The average degree of polymerization of (x) the base vinyl chlorideresin is preferably at least 800 and no greater than 5,000, and morepreferably at least 800 and no greater than 3,000. As a result of theaverage degree of polymerization of (a) the vinyl chloride resin beingin the range described above, a vinyl chloride resin molded productformed through powder molding of the vinyl chloride resin compositioncan be provided with favorable heat aging resistance. Note that theaverage degree of polymerization is measured in accordance with JISK6720-2.

Vinyl chloride resin particles are preferably used as (x) the base vinylchloride resin. No specific limitations are placed on the averageparticle diameter of the vinyl chloride resin particles used as (x) thebase vinyl chloride resin. The average particle diameter is preferablyat least 50 μm and no greater than 500 μm, more preferably at least 50μm and no greater than 250 μm, and particularly preferably at least 100μm and no greater than 200 μm. As a result of the average particlediameter of the vinyl chloride resin particles used as (x) the basevinyl chloride resin being in the range described above, powder fluidityof the vinyl chloride resin composition and smoothness of a vinylchloride resin molded product formed through powder molding of the vinylchloride resin composition are improved. The average particle diameteris measured in accordance with a sieving method using a JIS standardsieve prescribed by JIS Z8801.

The amount of (x) the base vinyl chloride resin in 100 mass % of (a) thevinyl chloride resin is normally at least 70 mass % and no greater than100 mass %, preferably at least 70 mass % and no greater than 99 mass %,more preferably at least 75 mass % and no greater than 95 mass %, andparticularly preferably at least 80 mass % and no greater than 92 mass%.

[Vinyl Chloride Resin Fine Particles]

The average particle diameter of (y) the vinyl chloride resin fineparticles is preferably at least 0.1 μm and no greater than 10 μm. Thestated average particle diameter improves powder fluidity of the vinylchloride resin composition. The average particle diameter of (y) thevinyl chloride resin fine particles is measured by a laser diffractionmethod in accordance with JIS Z8825 using, for example, a SALD-2300produced by Shimadzu Corporation.

The average degree of polymerization of a vinyl chloride resin forming(y) the vinyl chloride resin fine particles is preferably at least 500and no greater than 2,000, and more preferably at least 700 and nogreater than 1,500.

Moreover, the amount of (y) the vinyl chloride resin fine particles in100 mass % of (a) the vinyl chloride resin is normally at least 0 mass %and no greater than 30 mass %, preferably at least 1 mass % and nogreater than 30 mass %, more preferably at least 5 mass % and no greaterthan 25 mass %, and particularly preferably at least 8 mass % and nogreater than 20 mass %.

<Diester Plasticizer>

A compound represented by formula (1) shown below is used as (b) thediester plasticizer included in the vinyl chloride resin composition.

In formula (1), R¹ and R³ are monovalent hydrocarbon groups andpreferably monovalent aliphatic hydrocarbon groups that may be the sameor different, and R² is a divalent hydrocarbon group and preferably adivalent aliphatic hydrocarbon group.

R¹ and R³ in formula (1) each have, independently of one another, acarbon number that is preferably at least 2 and no greater than 24, morepreferably at least 4 and no greater than 20, further preferably atleast 7 and no greater than 17, and particularly preferably at least 7and no greater than 9.

Moreover, R² in formula (1) has a carbon number that is preferably atleast 1 and no greater than 14, more preferably at least 1 and nogreater than 12, further preferably at least 2 and no greater than 9,and particularly preferably at least 5 and no greater than 9.

Furthermore, R¹, R², and R³ in formula (1) preferably each have astraight chain ratio of at least 90 mol %, more preferably each have astraight chain ratio of at least 95 mol %, and particularly preferablyeach have a straight chain ratio of 100 mol %. The straight chain ratiosof R¹, R², and R³ are the proportions of straight chain hydrocarbongroups relative to all hydrocarbon groups for R¹, R², and R³,respectively.

Specific examples of straight chain hydrocarbon groups that can form R¹and R³ in formula (1) include a methyl group, an ethyl group, ann-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group,an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group,an n-undecyl group, an n-dodecyl group, an n-tridecyl group, ann-hexadecyl group, an n-pentadecyl group, an n-hexadecyl group, ann-heptadecyl group, and an n-stearyl group. Specific examples ofbranched hydrocarbon groups that can form R¹ and R³ in formula (1)include an i-propyl group, an i-butyl group, an i-pentyl group, ani-hexyl group, an i-heptyl group, an i-octyl group, an i-nonyl group, ani-decyl group, an i-undecyl group, an i-dodecyl group, an i-tridecylgroup, an i-hexadecyl group, an i-pentadecyl group, an i-hexadecylgroup, an i-heptadecyl group, an i-octadecyl group, a t-butyl group, at-pentyl group, a t-hexyl group, a t-heptyl group, a t-octyl group, at-nonyl group, a t-decyl group, a t-undecyl group, a t-dodecyl group, at-tridecyl group, a t-hexadecyl group, a t-pentadecyl group, at-hexadecyl group, a t-heptadecyl group, a t-octadecyl group, and a2-ethylhexyl group.

As a result of (b) the diester plasticizer being in the scope describedabove, a vinyl chloride resin molded product obtained through powdermolding of the presently disclosed vinyl chloride resin composition hassuperior flexibility at low temperatures and tensile characteristics.

Particularly in a situation in which (c) a trimellitate plasticizer isnot included as a plasticizer, the amount of (b) the diester plasticizerrelative to 100 parts by mass of (a) the vinyl chloride resin ispreferably at least 5 parts by mass and no greater than 200 parts bymass, more preferably at least 30 parts by mass and no greater than 180parts by mass, and particularly preferably at least 50 parts by mass andno greater than 150 parts by mass. As a result of the amount of (b) thediester plasticizer being in the range described above, a vinyl chlorideresin molded product formed through powder molding of the vinyl chlorideresin composition can be provided with favorable flexibility at lowtemperatures.

<Trimellitate Plasticizer>

The presently disclosed vinyl chloride resin composition may furtherinclude (c) a trimellitate plasticizer. Inclusion of (c) thetrimellitate plasticizer in the vinyl chloride resin compositionimproves the balance of fogging characteristics and flexibility of avinyl chloride resin molded product obtained through powder molding ofthe vinyl chloride resin composition.

It is preferable that (c) the trimellitate plasticizer is an estercompound of trimellitic acid and a monohydric alcohol.

Specific examples of (c) the trimellitate plasticizer includetri-n-hexyl trimellitate, tri-n-heptyl trimellitate, tri-n-octyltrimellitate, tri(2-ethylhexyl) trimellitate, tri-n-nonyl trimellitate,tri-n-decyl trimellitate, triisodecyl trimellitate, tri-n-undecyltrimellitate, tri-n-dodecyl trimellitate, and tri-n-alkyl trimellitates(esters including two or more types of alkyl groups having differingcarbon numbers of from 6 to 12 in molecules thereof).

One specific preferable example of (c) the trimellitate plasticizer is acompound represented by formula (2) shown below.

In formula (2), R⁴, R⁵, and R⁶ are alkyl groups that may be the same ordifferent.

A straight chain ratio of each of R⁴, R⁵, and R⁶ is preferably at least90 mol % and more preferably at least 95 mol %. The proportion of alkylgroups R⁴, R⁵, and R⁶ having a carbon number of no greater than 7relative to all alkyl groups R⁴, R⁵, and R⁶ is preferably at least 0 mol% and no greater than 10 mol %. The proportion of alkyl groups R⁴, R⁵,and R⁶ having a carbon number of 8 or 9 relative to all alkyl groups R⁴,R⁵, and R⁶ is preferably at least 5 mol % and no greater than 100 mol %,more preferably at least 40 mol % and no greater than 95 mol %, andparticularly preferably at least 75 mol % and no greater than 95 mol %.The proportion of alkyl groups R⁴, R⁵, and R⁶ having a carbon number of10 relative to all alkyl groups R⁴, R⁵, and R⁶ is preferably at least 0mol % and no greater than 95 mol %, more preferably at least 5 mol % andno greater than 60 mol %, and particularly preferably at least 5 mol %and no greater than 25 mol %. The proportion of alkyl groups R⁴, R⁵, andR⁶ having a carbon number of at least 11 relative to all alkyl groupsR⁴, R⁵, and R⁶ is preferably at least 0 mol % and no greater than 10 mol%. Note that the straight chain ratios of R⁴, R⁵, and R⁶ are theproportions of straight chain alkyl groups relative to all alkyl groupsfor R⁴, R⁵, and R⁶, respectively.

Specific examples of straight chain alkyl groups that can form R⁴, R⁵,and R⁶ in formula (2) are the same as the specific examples of straightchain hydrocarbon groups that can form R¹ and R³ in formula (1).Moreover, specific examples of branched alkyl groups that can form R⁴,R⁵, and R⁶ in formula (2) are the same as the specific examples of thebranched hydrocarbon groups than can form R¹ and R³ in formula (1).

Note that (c) the trimellitate plasticizer may be a single compound ormay be a mixture.

The total amount of (b) the diester plasticizer and (c) the trimellitateplasticizer relative to 100 parts by mass of (a) the vinyl chlorideresin is preferably at least 5 parts by mass and no greater than 200parts by mass, more preferably at least 30 parts by mass and no greaterthan 180 parts by mass, and particularly preferably at least 50 parts bymass and no greater than 150 parts by mass. As a result of the totalamount of (b) the diester plasticizer and (c) the trimellitateplasticizer being in the range described above, a vinyl chloride resinmolded product formed through powder molding of the vinyl chloride resincomposition can be provided with favorable flexibility at lowtemperatures.

From a viewpoint of providing favorable fogging characteristics to thevinyl chloride resin molded product formed through powder molding of thevinyl chloride resin composition, a blending ratio of (b) the diesterplasticizer relative to (c) the trimellitate plasticizer (diesterplasticizer/trimellitate plasticizer), expressed as a mass ratio, ispreferably no greater than 99/1, more preferably no greater than 50/50,further preferably no greater than 35/65, and particularly preferably nogreater than 20/80. Furthermore, from a viewpoint of providing afavorable balance of high levels of flexibility at low temperatures andfogging characteristics to the vinyl chloride resin molded productformed through powder molding of the vinyl chloride resin composition,the blending ratio of (b) the diester plasticizer relative to (c) thetrimellitate plasticizer (diester plasticizer/trimellitate plasticizer),expressed as a mass ratio, is preferably at least 1/99, more preferablyat least 5/95, and particularly preferably at least 15/85.

<Additives>

Besides (a) the vinyl chloride resin, (b) the diester plasticizer, and(c) the trimellitate plasticizer, the presently disclosed vinyl chlorideresin composition may include various additives. Although no specificlimitations are placed on these additives, examples of additives thatmay be used include plasticizers other than (b) the diester plasticizerand (c) the trimellitate plasticizer (hereinafter also referred to as“other plasticizers”), perchloric acid-treated hydrotalcite, zeolites,fatty acid metal salts, dusting agents (powder fluidity modifiers) otherthan (y) the vinyl chloride resin fine particles (hereinafter alsoreferred to as “other dusting agents”), and other additives.

[Other Plasticizers]

Examples of other plasticizers besides (b) the diester plasticizer and(c) the trimellitate plasticizer that may be included in the presentlydisclosed vinyl chloride resin composition include primary plasticizersand secondary plasticizers listed below.

Examples of so-called primary plasticizers include:

pyromellitate plasticizers such as tetra-n-hexyl pyromellitate,tetra-n-heptyl pyromellitate, tetra-n-octyl pyromellitate,tetra(2-ethylhexyl) pyromellitate, tetra-n-nonyl pyromellitate,tetra-n-decyl pyromellitate, tetraisodecyl pyromellitate,tetra-n-undecyl pyromellitate, tetra-n-dodecyl pyromellitate, andtetra-n-alkyl pyromellitates (esters including two or more types ofalkyl groups having differing carbon numbers of from 6 to 12 inmolecules thereof);

epoxidized vegetable oils such as epoxidized soybean oil and epoxidizedlinseed oil;

phthalic acid derivatives such as dimethyl phthalate, diethyl phthalate,di-n-butyl phthalate, diisobutyl phthalate, di-n-heptyl phthalate,di(2-ethylhexyl) phthalate, di-n-octyl phthalate, di-n-nonyl phthalate,di-n-decyl phthalate, diisodecyl phthalate, di-n-undecyl phthalate,di-n-dodecyl phthalate, di-n-tridecyl phthalate, dicyclohexyl phthalate,diphenyl phthalate, dibenzyl phthalate, and n-butylbenzyl phthalate;

isophthalic acid derivatives such as dimethyl isophthalate,di(2-ethylhexyl) isophthalate, and diisooctyl isophthalate;

tetrahydrophthalic acid derivatives such as di(2-ethylhexyl)tetrahydrophthalate, di-n-octyl tetrahydrophthalate, and diisodecyltetrahydrophthalate;

adipic acid derivatives such as di-n-butyl adipate, di(2-ethylhexyl)adipate, diisononyl adipate, and diisodecyl adipate;

maleic acid derivatives such as dimethyl maleate, diethyl maleate,di-n-butyl maleate, and di(2-ethylhexyl) maleate;

fumaric acid derivatives such as di-n-butyl fumarate anddi(2-ethylhexyl) fumarate;

citric acid derivatives such as triethyl citrate, tri-n-butyl citrate,acetyltriethyl citrate, and acetyltri(2-ethylhexyl) citrate;

itaconic acid derivatives such as monomethyl itaconate, mono-n-butylitaconate, dimethyl itaconate, diethyl itaconate, di-n-butyl itaconate,and di(2-ethylhexyl) itaconate;

ricinoleic acid derivatives such as methylacetyl ricinoleate,n-butylacetyl ricinoleate, glyceryl monoricinoleate, and diethyleneglycol monoricinoleate;

stearic acid derivatives such as n-butyl stearate and diethylene glycoldistearate;

phosphoric acid derivatives such as triethyl phosphate, tri-n-butylphosphate, tri(2-ethylhexyl) phosphate, tri-n-butoxyethyl phosphate,triphenyl phosphate, cresyl diphenyl phosphate, tricresyl phosphate,trixylenyl phosphate, and tris(chloroethyl) phosphate;

glycerin derivatives such as glycerol monoacetate, glycerol triacetate,and glycerol tributyrate;

epoxy derivatives such as epoxy hexahydro diisodecyl phthalate, epoxytriglyceride, epoxidized octyl oleate, and epoxidized decyl oleate; and

polyester plasticizers such as adipic acid polyesters, sebacic acidpolyesters, and phthalic acid polyesters.

Examples of so-called secondary plasticizers include chlorinatedparaffin, fatty acid esters of glycol such as triethylene glycoldicaprylate, n-butyl epoxy stearate, phenyl oleate, and methyldihydroabietate.

Any one or any two or more of these other plasticizers may be used inthe presently disclosed vinyl chloride resin composition. In a situationin which a secondary plasticizer is used, a primary plasticizer ofequivalent or greater mass is preferably used in combination with thesecondary plasticizer.

Among the other plasticizers listed above, pyromellitate plasticizersand epoxidized plant oils are preferable, epoxidized plant oils are morepreferable, and epoxidized soybean oil is particularly preferable.

The amount of the other plasticizers described above relative to 100parts by mass of (a) the vinyl chloride resin is preferably at least 0.1parts by mass and no greater than 30 parts by mass, more preferably atleast 0.5 parts by mass and no greater than 20 parts by mass, andparticularly preferably at least 1 part by mass and no greater than 10parts by mass. As a result of the amount of plasticizers other than (b)the diester plasticizer and (c) the trimellitate plasticizer being inthe range described above, a vinyl chloride resin molded product formedthrough powder molding of the vinyl chloride resin composition can beprovided with favorable flexibility at low temperatures.

[Perchloric Acid-Treated Hydrotalcite]

The perchloric acid-treated hydrotalcite that may be included in thepresently disclosed vinyl chloride resin composition can be easilyproduced by, for example, addition and mixing of hydrotalcite with adilute aqueous solution of perchloric acid, followed by filtration,dehydration, and drying as required. Through this process, at least someof the carbonate anions (CO₃ ²⁻) in the hydrotalcite are substitutedwith perchlorate anions (ClO₄ ⁻) (note that 2 mol of perchlorate anionsare substituted per 1 mol of carbonate anions). The molar ratio ofhydrotalcite and perchloric acid may be freely set, although a ratio offrom 0.1 mol to 2 mol of perchloric acid relative to 1 mol ofhydrotalcite is typical.

The substitution ratio of carbonate anions in the untreated(unsubstituted) hydrotalcite by perchlorate anions is preferably atleast 50 mol %, more preferably at least 70 mol %, and particularlypreferably at least 85 mol %. Moreover, the substitution ratio ofcarbonate anions in the untreated (unsubstituted) hydrotalcite byperchlorate anions is preferably no greater than 95 mol %. As a resultof the substitution ratio of carbonate anions in the untreated(unsubstituted) hydrotalcite by perchlorate anions being in the rangedescribed above, a vinyl chloride resin molded product formed throughpowder molding of the vinyl chloride resin composition can be providedwith favorable flexibility at low temperatures.

Hydrotalcite is a non-stoichiometric compound represented by a generalformula: [Mg_(1-x)Al_(x)(OH)₂]^(x+)[(CO₃)_(x/2).mH₂O]^(x−), and is aninorganic substance having a layered crystal structure formed by apositively charged basic layer of [Mg_(1-x)Al_(x)(OH)₂]^(x+) and anegatively charged intermediate layer of [(CO₃)_(x/2).mH₂O]^(x−). In thegeneral formula shown above, x represents a number that is greater than0 and no greater than 0.33. Natural hydrotalcite is represented byMg₆Al₂(OH)₁₆CO₃.4H₂O. On the other hand, a synthetic hydrotalciterepresented by Mg_(4.5)Al₂(OH)₁₃CO₃.3.5H₂O is commercially available.Synthetic hydrotalcite can for example be synthesized by a methoddescribed in JP S61-174270 B.

The amount of the perchloric acid-treated hydrotalcite relative to 100parts by mass of (a) the vinyl chloride resin is preferably at least 0.5parts by mass and no greater than 7 parts by mass, more preferably atleast 1 part by mass and no greater than 6 parts by mass, andparticularly preferably at least 1.5 parts by mass and no greater than5.5 parts by mass. As a result of the amount of the perchloricacid-treated hydrotalcite being in the range described above, a vinylchloride resin molded product formed through powder molding of the vinylchloride resin composition can be provided with favorable flexibility atlow temperatures.

[Zeolite]

The presently disclosed vinyl chloride resin composition may include azeolite as a stabilizer. A zeolite is a compound represented by ageneral formula: M_(x/n).[(AlO₂)_(x).(SiO₂)_(y)].zH₂O (in the generalformula, M is a metal ion of valency n, x+y is the number of tetrahedraper unit cell, and z is the number of moles of water). Examples of M inthe general formula include monovalent and divalent metals such as Na,Li, Ca, Mg, and Zn, and mixtures thereof.

No specific limitations are placed on the amount of the zeolite that isincluded. However, the amount of the zeolite relative to 100 parts bymass of (a) the vinyl chloride resin is preferably at least 0.1 parts bymass and no greater than 5 parts by mass.

[Fatty Acid Metal Salt]

The fatty acid metal salt that may be included in the presentlydisclosed vinyl chloride resin composition is preferably a metal salt ofa monobasic fatty acid, more preferably a metal salt of a monobasicfatty acid having a carbon number of 12-24, and particularly preferablya metal salt of a monobasic fatty acid having a carbon number of 15-21.Specific examples of the fatty acid metal salt include lithium stearate,magnesium stearate, aluminum stearate, calcium stearate, strontiumstearate, barium stearate, zinc stearate, calcium laurate, bariumlaurate, zinc laurate, barium 2-ethylhexanoate, zinc 2-ethylhexanoate,barium ricinoleate, and zinc ricinoleate. The metal in the fatty acidmetal salt is preferably a metal that can produce polyvalent cations,more preferably a metal that can produce divalent cations, furtherpreferably a metal from periods 3-6 of the periodic table that canproduce divalent cations, and particularly preferably a metal fromperiod 4 of the periodic table that can produce divalent cations. Thefatty acid metal salt is most preferably zinc stearate.

The amount of the fatty acid metal salt relative to 100 parts by mass of(a) the vinyl chloride resin is preferably at least 0.05 parts by massand no greater than 5 parts by mass, more preferably at least 0.1 partsby mass and no greater than 1 part by mass, and particularly preferablyat least 0.1 parts by mass and no greater than 0.5 parts by mass. As aresult of the amount of the fatty acid metal salt being in the rangedescribed above, a vinyl chloride resin molded product formed throughpowder molding of the vinyl chloride resin composition can be providedwith favorable flexibility at low temperatures and a color differencevalue thereof can be reduced.

[Other Dusting Agents]

Examples of other dusting agents (powder fluidity modifiers) besides (y)the vinyl chloride resin fine particles that may be included in thepresently disclosed vinyl chloride resin composition include: inorganicfine particles such as calcium carbonate, talc, and aluminum oxide; andorganic fine particles such as polyacrylonitrile resin fine particles,poly(meth)acrylate resin fine particles, polystyrene resin fineparticles, polyethylene resin fine particles, polypropylene resin fineparticles, polyester resin fine particles, and polyamide resin fineparticles. Among these examples, inorganic fine particles having anaverage particle diameter of at least 10 nm and no greater than 100 nmare preferable. No specific limitations are placed on the amount of thedusting agent that is included. In the case of a dusting agent that isnot (y) the vinyl chloride resin fine particles, the amount of thedusting agent relative to 100 parts by mass of (a) the vinyl chlorideresin is preferably no greater than 30 parts by mass and more preferablyat least 10 parts by mass and no greater than 25 parts by mass.

[Other Additives]

Examples of other additives that may be included in the presentlydisclosed vinyl chloride resin composition include colorants, impactmodifiers, perchloric acid compounds other than perchloric acid-treatedhydrotalcite (for example, sodium perchlorate and potassiumperchlorate), antioxidants, fungicides, flame retardants, antistaticagents, fillers, light stabilizers, foaming agents, and β-diketones.

Specific examples of colorants include quinacridone pigments, perylenepigments, condensed polyazo pigments, isoindolinone pigments, copperphthalocyanine pigments, titanium white, and carbon black. Any one ofthese pigments or any two or more of these pigments may be used.

A quinacridone pigment is obtained through concentrated sulfuric acidtreatment of a p-phenylene dianthranilic acid and has a hue fromyellowish red to reddish purple. Specific examples of quinacridonepigments include quinacridone red, quinacridone magenta, andquinacridone violet.

A perylene pigment is obtained through a condensation reaction ofperylene-3,4,9,10-tetracarboxylic anhydride and an aromatic primaryamine and has a hue from red to red-purple/brown. Specific examples ofperylene pigments include perylene red, perylene orange, perylenemaroon, perylene vermilion, and perylene bordeaux.

A condensed polyazo pigment is obtained through condensation of an azopigment in a solvent to achieve a high molecular weight and has a hue ofa yellow or red pigment. Specific examples of condensed polyazo pigmentsinclude polyazo red, polyazo yellow, chromophthal orange, chromophthalred, and chromophthal scarlet.

An isoindolinone pigment is obtained through a condensation reaction of4,5,6,7-tetrachloroisoindolinone and an aromatic primary amine and has ahue from greenish yellow to red/brown. A specific example of anisoindolinone pigment is isoindolinone yellow.

A copper phthalocyanine pigment is a pigment in which copper iscoordinated with a phthalocyanine and has a hue from yellowish green tobright blue. Specific examples of copper phthalocyanine pigments includephthalocyanine green and phthalocyanine blue.

Titanium white is a white pigment made from titanium dioxide. Titaniumwhite has high opacity and exists in anatase form and rutile form.

Carbon black is a black pigment having carbon as a main component andalso including oxygen, hydrogen, and nitrogen. Specific examples ofcarbon black include thermal black, acetylene black, channel black,furnace black, lamp black, and bone black.

Specific examples of impact modifiers include anacrylonitrile-butadiene-styrene copolymer, a methylmethacrylate-butadiene-styrene copolymer, a chlorinated polyethylene, anethylene-vinyl acetate copolymer, and a chlorosufonated polyethylene.One impact modifier or two or more impact modifiers may be used in thepresently disclosed vinyl chloride resin composition. Note that theimpact modifier is dispersed as a heterogeneous phase of fine elasticparticles in the vinyl chloride resin composition. In the vinyl chlorideresin composition, polar groups and chains graft polymerized with theelastic particles are compatible with (a) the vinyl chloride resin andimprove impact resistance of the vinyl chloride resin composition.

Specific examples of antioxidants include phenolic antioxidants,sulfuric antioxidants, and phosphoric antioxidants.

Specific examples of fungicides include aliphatic ester fungicides,hydrocarbon fungicides, organic nitrogen fungicides, and organicnitrogen sulfur fungicides.

Specific examples of flame retardants include halogen-containing flameretardants such as chlorinated paraffin, phosphoric flame retardantssuch as phosphate esters, and inorganic hydroxides such as magnesiumhydroxide and aluminum hydroxide.

Specific examples of antistatic agents include: anionic antistaticagents such as fatty acid salts, higher alcohol sulfuric acid esters,and sulfonic acid salts; cationic antistatic agents such as aliphaticamine salts and quaternary ammonium salts; and non-ionic antistaticagents such as polyoxyethylene alkyl ethers and polyoxyethylene alkylphenol ethers.

Specific examples of fillers include silica, talc, mica, calciumcarbonate, and clay.

Specific examples of light stabilizers include ultraviolet absorbersbased on benzotriazoles, benzophenone, and nickel chelate, and hinderedamine light stabilizers.

Specific examples of foaming agents include: organic foaming agents suchas azo compounds (for example, azodicarbonamides andazobisisobutyronitrile), nitroso compounds (for example,N,N′-dinitrosopentamethylenetetramine), and sulfonyl hydrazide compounds(for example p-toluenesulfonyl hydrazide and p,p-oxybis(benzenesulfonylhydrazide)); and gaseous foaming agents such as chlorofluorocarbons,carbon dioxide gas, water, and volatile hydrocarbons (for examplepentane), and microcapsules containing any of these gaseous foamingagents.

A β-diketone can be used to effectively suppress variation in initialcolor of a vinyl chloride resin molded product obtained through powdermolding of the presently disclosed vinyl chloride resin composition.Specific examples of β-diketones include dibenzoylmethane,stearoylbenzoylmethane, and palmitoylbenzoylmethane. Any one of theseβ-diketones may be used alone or a combination of any two or more ofthese β-diketones may be used.

No specific limitations are placed on the amount of the β-diketone thatis included. However, the amount of the β-diketone relative to 100 partsby mass of (a) the vinyl chloride resin is preferably at least 0.1 partsby mass and no greater than 5 parts by mass.

<Production Method of Vinyl Chloride Resin Composition>

The presently disclosed vinyl chloride resin composition can be producedby mixing the components described above.

No specific limitations are placed on the method used to mix (a) thevinyl chloride resin, (b) the diester plasticizer, and additionally (c)the trimellitate plasticizer and other additives as required. Oneexample of a preferable mixing method involves mixing all of thecomponents with the exception of the plasticizer and the dusting agent(including (y) the vinyl chloride resin fine particles) by dry blendingand subsequently mixing in the plasticizer and the dusting agent inorder. The dry blending is preferably carried out using a Henschelmixer. The temperature during dry blending is preferably at least 50° C.and no greater than 100° C., and more preferably at least 70° C. and nogreater than 80° C.

(Vinyl Chloride Resin Molded Product)

A presently disclosed vinyl chloride resin molded product is obtainedthrough powder molding of the presently disclosed vinyl chloride resincomposition described above and is preferably obtained through powderslush molding of the vinyl chloride resin composition. The moldtemperature during powder slush molding is preferably at least 200° C.and no greater than 300° C., and more preferably at least 220° C. and nogreater than 280° C.

In production of the presently disclosed vinyl chloride resin moldedproduct, the presently disclosed vinyl chloride resin composition is forexample sprinkled onto a mold having a temperature in the aforementionedrange. The vinyl chloride resin composition is initially left for atleast 5 seconds and no greater than 30 seconds and, after shaking offany excess vinyl chloride resin composition, is then further left for atleast 30 seconds and no greater than 3 minutes. The mold is subsequentlycooled to at least 10° C. and no greater than 60° C. and the presentlydisclosed vinyl chloride resin molded product obtained thereby isremoved from the mold.

The presently disclosed vinyl chloride resin molded product is highlysuitable for use as a surface skin of an automobile interior materialsuch as an instrument panel or a door trim.

(Laminate)

A presently disclosed laminate is obtainable by stacking the presentlydisclosed vinyl chloride resin molded product with a foamed polyurethanemolded product. Examples of stacking methods that can be adoptedinclude: a method in which the vinyl chloride resin molded product andthe foamed polyurethane molded product are prepared separately and aresubsequently joined together by, for example, thermal fusion bonding,thermal adhesion, or using a commonly known adhesive; and a method inwhich raw materials of the foamed polyurethane molded product such as anisocyanate and a polyol are caused to react on the vinyl chloride resinmolded product so as to polymerize while carrying out polyurethanefoaming by a commonly known method to directly form the foamedpolyurethane molded product on the vinyl chloride resin molded product.The latter of these methods is more suitable because it involves asimple process and enables laminates of various different shapes to beobtained while ensuring reliable adhesion of the vinyl chloride resinmolded product and the foamed polyurethane molded product.

The presently disclosed laminate is highly suitable for use as anautomobile interior material such as an instrument panel or a door trim.

EXAMPLES

The present disclosure is described in more detail through the followingexamples but is not limited to these examples.

Diester plasticizers used in the following examples and comparativeexamples were prepared as described below.

Production Example 1 Production of 1,9-nonanediol diester plasticizer

A four-neck flask equipped with a stirrer, a thermometer, a nitrogen gasblowing tube, and a moisture fractional distillation receiver includinga condenser was charged with 0.80 parts by mass (5.00 molar parts) of1,9-nonanediol, 1.08 parts by mass (7.52 molar parts) of 1-octanoicacid, 0.54 parts by mass (2.98 molar parts) of 1-decanoic acid, 5 mass %of xylene relative to the total charged mass, and 0.2 mass % ofp-toluenesulfonic acid relative to the total charged mass. Anesterification reaction was carried out at 160° C. until the theoreticalamount of produced water had collected in the moisture fractionaldistillation receiver.

After the reaction, excess acid and xylene were removed by distillationto obtain an esterified crude product. Next, the resultant esterifiedcrude product was neutralized by a saturated aqueous solution of sodiumhydrogen carbonate and was washed with water until neutral.

Thereafter, the water-washed esterified crude product was treated withactivated carbon and the activated carbon was removed by filtration toyield 1.72 parts by mass of a 1,9-nonanediol diester plasticizer. Theresultant 1,9-nonanediol diester plasticizer had an acid value of 0.1mgKOH/g and a saponification value of 263.

Production Example 2 Production of 3-methyl-1,5-pentanediol diesterplasticizer

A four-neck flask equipped with a stirrer, a thermometer, a nitrogen gasblowing tube, and a moisture fractional distillation receiver includinga condenser was charged with 0.59 parts by mass of3-methyl-1,5-pentanediol, 1.09 parts by mass of 1-octanoic acid, 0.51parts by mass of 1-decanoic acid, 5 mass % of xylene relative to thetotal charged mass, and 0.2 mass % of p-toluenesulfonic acid relative tothe total charged mass. An esterification reaction was carried out at200° C. until the theoretical amount of produced water had collected inthe moisture fractional distillation receiver.

After the reaction, excess acid and xylene were removed by distillationto obtain an esterified crude product. Next, the resultant esterifiedcrude product was neutralized by a saturated aqueous solution of sodiumhydrogen carbonate and was washed with water until neutral.

Thereafter, the water-washed esterified crude product was treated withactivated carbon and the activated carbon was removed by filtration toyield 1.55 parts by mass of a 3-methyl-1,5-pentanediol diesterplasticizer. The resultant 3-methyl-1,5-pentanediol diester plasticizerhad an acid value of 0.2 mgKOH/g and a saponification value of 292.

Production Example 3 Production of 1,6-hexanediol diester plasticizer

A four-neck flask equipped with a stirrer, a thermometer, a nitrogen gasblowing tube, and a moisture fractional distillation receiver includinga condenser was charged with 0.59 parts by mass of 1,6-hexanediol, 1.09parts by mass of 1-octanoic acid, 0.51 parts by mass of 1-decanoic acid,5 mass % of xylene relative to the total charged mass, and 0.2 mass % ofp-toluenesulfonic acid relative to the total charged mass. Anesterification reaction was carried out at 200° C. until the theoreticalamount of produced water had collected in the moisture fractionaldistillation receiver.

After the reaction, excess acid and xylene were removed by distillationto obtain an esterified crude product. Next, the resultant esterifiedcrude product was neutralized by a saturated aqueous solution of sodiumhydrogen carbonate and was washed with water until neutral.

Thereafter, the water-washed esterified crude product was treated withactivated carbon and the activated carbon was removed by filtration toyield 1.55 parts by mass of a 1,6-hexanediol diester plasticizer. Theresultant 1,6-hexanediol diester plasticizer had an acid value of 0.1mgKOH/g and a saponification value of 292.

Example 1 and Comparative Example 1

Ingredients shown in Table 1 with the exception of the plasticizers(trimellitate plasticizer, 1,9-nonanediol diester plasticizer, andepoxidized soybean oil) and vinyl chloride resin fine particles used asthe dusting agent were added into a Henschel mixer and mixed. Theplasticizers were added to the mixture after increasing the temperatureof the mixture to 80° C. and the mixture was dried up (i.e., theaforementioned mixture changed to a dry state through absorption of theplasticizers by vinyl chloride resin particles used as the base vinylchloride resin). Thereafter, once the dried-up mixture had been cooledto 70° C. or lower, the vinyl chloride resin fine particles used as thedusting agent were added to the mixture to produce a vinyl chlorideresin composition.

The resultant vinyl chloride resin composition was sprinkled onto atextured mold that was heated to 250° C. and after being left to meltfor 13 seconds, excess vinyl chloride resin composition was shaken off.Next, the mold was placed in an oven set to 200° C. and once 60 secondshad passed, was cooled with cooling water. Once the mold had cooled to40° C., a vinyl chloride resin molded sheet of 145 mm×175 mm×1 mm wasremoved from the mold. Various properties of the resultant vinylchloride resin molded sheet were measured as described below. Theresults are shown in Table 1.

(1) Tensile Stress and Tensile Elongation

The vinyl chloride resin molded sheet was punched with a No. 1 dumbbellprescribed by JIS K6251, and tensile stress and tensile elongationthereof were measured in accordance with JIS K7113 at a tension rate of200 mm/minute and at 23° C.

(2) Viscoelasticity Test

An obtained vinyl chloride resin molded sheet was punched to dimensionsof 10 mm×40 mm and a loss modulus peak top temperature was measured inaccordance with JIS K7244-4 at a frequency of 10 Hz, a measurementtemperature range of from −90° C. to +100° C., and a heating rate of 2°C./minute. Note that a low peak top temperature indicates that a vinylchloride resin molded sheet has superior flexibility at lowtemperatures.

TABLE 1 Comparative Example 1 Example 1 Composition Base vinyl chlorideresin⁽¹⁾ 100.0 100.0 (parts by mass) Trimellitate plasticizer⁽²⁾ — 130.01,9-Nonanediol diester 130.0 — plasticizer Epoxidized soybean oil⁽³⁾ 5.05.0 Perchloric acid-treated 5.0 5.0 hydrotalcite⁽⁴⁾ Zeolite⁽⁵⁾ 1.0 1.0Stearoylbenzoylmethane 0.3 0.3 (β-diketone)⁽⁶⁾ Zinc stearate⁽⁷⁾ 0.2 0.2Vinyl chloride resin fine 20.0 20.0 particles (dusting agent)⁽⁸⁾Pigment⁽⁹⁾ 4.0 4.0 Tensile stress [MPa] 7.4 9.2 Tensile elongation [%]350 360 Viscoelasticity test (peak top −54.8 −46.9 temperature) [° C.]⁽¹⁾ZEST 2500Z (vinyl chloride resin particles, average degree ofpolymerization 2,500, average particle diameter 130 μm) produced by ShinDai-ichi Vinyl Corporation ⁽²⁾TRIMEX N-08 produced by Kao Corporation⁽³⁾ADK CIZER O-130S produced by ADEKA Corporation ⁽⁴⁾ALCAMIZER 5produced by Kyowa Chemical Industry Co., Ltd. ⁽⁵⁾MIZUKALIZER DS producedby Mizusawa Industrial Chemicals Ltd. ⁽⁶⁾Karenz DK-1 produced by ShowaDenko K.K. ⁽⁷⁾SAKAI SZ2000 produced by Sakai Chemical Industry Co., Ltd.⁽⁸⁾ZEST PQLTX (vinyl chloride resin fine particles, average degree ofpolymerization 800, average particle diameter 2 μm) produced by ShinDai-ichi Vinyl Corporation ⁽⁹⁾DA PX-1720 Black (A) produced byDainichiseika Color and Chemicals Mfg. Co., Ltd.

A molded product (vinyl chloride resin molded sheet) obtained throughpowder slush molding of the vinyl chloride resin composition in Example1 had a low loss modulus peak top temperature and thus had superiorflexibility at low temperatures. The molded product also had superiortensile characteristics.

In contrast, a molded product obtained through powder slush molding ofthe vinyl chloride resin composition in Comparative Example 1, which didnot include a diester plasticizer, had similar tensile characteristicsto the molded product in Example 1, but had a high loss modulus peak toptemperature compared to the molded product in Example 1 and thus hadpoor flexibility at low temperatures.

Examples 2-11 and Comparative Examples 1 and 2

Ingredients shown in Tables 2-4 with the exception of the plasticizers(trimellitate plasticizer, 1,9-nonanediol diester plasticizer,1,3-propanediol diester plasticizer, 3-methyl-1,5-pentanediol diesterplasticizer, 1,6-hexanediol diester plasticizer, and epoxidized soybeanoil) and vinyl chloride resin fine particles used as the dusting agentwere added into a Henschel mixer and mixed. The plasticizers were addedto the mixture after increasing the temperature of the mixture to 80° C.and the mixture was dried up (i.e., the aforementioned mixture changedto a dry state through absorption of the plasticizers by vinyl chlorideresin particles used as the base vinyl chloride resin). Thereafter, oncethe dried-up mixture had been cooled to 70° C. or lower, the vinylchloride resin fine particles used as the dusting agent were added tothe mixture to produce a vinyl chloride resin composition.

The resultant vinyl chloride resin composition was sprinkled onto atextured mold that was heated to 250° C. and after being left to meltfor a time adjusted to give a vinyl chloride resin molded sheetthickness of 1 mm (specifically, from 8 seconds to 18 seconds), excessvinyl chloride resin composition was shaken off. Next, the mold wasplaced in an oven set to 200° C. and was cooled with cooling water once60 seconds had passed. Once the mold had cooled to 40° C., a vinylchloride resin molded sheet of 145 mm×175 mm×1 mm was removed from themold. Various properties of the resultant vinyl chloride resin moldedsheet were measured as described below. However, a post-heating tensiletest was not carried out for Examples 2-6 and Comparative Example 1.Furthermore, Examples 7-9 were only evaluated for tensile stress andtensile elongation at 23° C. and viscoelasticity. Also, a fogging testwas not carried out for Examples 10 and 11 and Comparative Example 2.

The results are shown in Tables 2-4.

(3) Initial Tensile Test

The vinyl chloride resin molded sheet was punched with a No. 1 dumbbellprescribed by JIS K6251, and tensile stress and tensile elongationthereof were measured in accordance with JIS K7113 at a tension rate of200 mm/minute and at temperatures of 23° C. and −35° C. Note that a hightensile elongation at −35° C. indicates that a vinyl chloride resinmolded sheet has superior flexibility at low temperatures.

(4) Post-Heating Tensile Test

A measurement sample was prepared as follows. Two obtained vinylchloride resin molded sheets was placed in a mold having dimensions of200 mm×300 mm×10 mm with a textured surface below the molded sheets suchthat the molded sheets did not overlap one another. A mixed solution wasprepared by mixing polymethylene polyphenylene polyisocyanate (polymericMDI) with a polyol mixture in a ratio determined to give an isocyanateindex of 98. The polyol mixture was composed of 50 parts by mass of apropylene glycol PO (propylene oxide)/EO (ethylene oxide) block adduct(hydroxyl value 28, terminal EO unit content 10%, internal EO unitcontent 4%), 50 parts by mass of a glycerin PO/EO block adduct (hydroxylvalue 21, terminal EO unit content 14%), 2.5 parts by mass of water, 0.2parts by mass of an ethylene glycol solution of triethylenediamine(product name: TEDA-L33, produced by Tosoh Corporation), 1.2 parts bymass of triethanolamine, 0.5 parts by mass of triethylamine, and 0.5parts by mass of a foam stabilizer (product name: F-122, produced byShin-Etsu Chemical Co., Ltd.). Thereafter, the resultant mixed solutionwas poured onto the two vinyl chloride resin molded sheets and the moldwas covered with an aluminum plate of 348 mm×255 mm×10 mm to seal themold. After 5 minutes, a sample (laminate) was formed, in the mold, of asurface skin formed by a vinyl chloride resin molded sheet having athickness of 1 mm lined with a foamed polyurethane molded product havinga thickness of 9 mm and a density of 0.18 g/cm³. The resultant samplewas removed from the mold.

Thereafter, the resultant sample was placed in an oven and after thesample was heated for 250 hours at 130° C., the foamed polyurethanelayer was peeled from the sample. Tensile stress and tensile elongationof the sample were measured at temperatures of 23° C. and −35° C. in thesame way as in the initial tensile test described above in section (3).Note that a high tensile elongation at −35° C. indicates that a vinylchloride resin molded sheet has superior flexibility at lowtemperatures.

(5) Viscoelasticity Test

An obtained vinyl chloride resin molded sheet was punched to dimensionsof 10 mm×40 mm and a loss modulus peak top temperature was measured inaccordance with JIS K7244-4 at a frequency of 10 Hz, a measurementtemperature range of from −90° C. to +100° C., and a heating rate of 2°C./minute. Note that a low peak top temperature indicates that a vinylchloride resin molded sheet has superior flexibility at lowtemperatures.

(6) Low-Temperature Embrittlement Test

An obtained vinyl chloride resin molded sheet was punched to dimensionsof 6 mm×38 mm and an embrittlement temperature was obtained inaccordance with JIS K7216 using test temperature intervals of 2° C. Notethat a low embrittlement temperature indicates that a vinyl chlorideresin molded sheet has superior flexibility at low temperatures.

(7) Fogging Test

An obtained vinyl chloride resin molded sheet was punched into a circlehaving a diameter of 80 mm and, using a device in accordance with thestandard ISO6452, the vinyl chloride resin molded sheet was placed in atest bottle heated to 100° C., a glass plate cooled to 20° C. was setover an opening of the test bottle, and a fogging test was carried outfor 3 hours. After the test, the glass plate was left to stand for 1hour at a temperature of 23° C. and a humidity of 50% and then 60°reflectance thereof was measured using a glossiness test device (GP-60produced by Tokyo Denshoku Co., Ltd.). The 60° reflectance of the glassplate was also measured before the test and glossiness retention (%) ofthe glass plate was calculated using the following equation. Note thathigh glossiness retention indicates that a vinyl chloride resin moldedsheet has superior fogging characteristics.Glossiness retention (%)=100×[(Post-test glass plateglossiness)/(Pre-test glass plate glossiness)]

TABLE 2 Comparative Example 2 Example 3 Example 4 Example 5 Example 6Example 1 Composition Base vinyl chloride resin⁽¹⁾ 100.0 100.0 100.0100.0 100.0 100.0 (parts by mass) Trimellitate plasticizer⁽²⁾ 125.0120.0 110.0 90.0 70.0 130.0 1,9-Nonanediol diester plasticizer 5.0 10.020.0 40.0 60.0 — Epoxidized soybean oil⁽³⁾ 5.0 5.0 5.0 5.0 5.0 5.0Perchloric acid-treated hydrotalcite⁽⁴⁾ 5.0 5.0 5.0 5.0 5.0 5.0Zeolite⁽⁵⁾ 1.0 1.0 1.0 1.0 1.0 1.0 Stearoylbenzoylmethane(β-diketone)⁽⁶⁾ 0.3 0.3 0.3 0.3 0.3 0.3 Zinc stearate⁽⁷⁾ 0.2 0.2 0.2 0.20.2 0.2 Vinyl chloride resin fine particles 20.0 20.0 20.0 20.0 20.020.0 (dusting agent)⁽⁸⁾ Pigment⁽⁹⁾ 4.0 4.0 4.0 4.0 4.0 4.0 Tensilestress (initial) @23° C. [MPa] 9.8 9.4 9.1 8.4 8.2 9.2 Tensile stress(initial) @−35° C. [MPa] 20.8 20.2 19.8 20.7 20.6 20.3 Tensileelongation (initial) @23° C. [%] 360 350 350 360 370 360 Tensileelongation (initial) @−35° C. [%] 200 200 220 230 210 190Viscoelasticity test (peak top temperature) [° C.] −48.8 −51.0 −54.8−54.7 −52.7 −46.9 Embrittlement temperature [° C.] −49.8 −51.4 −55.0−56.2 −54.0 −49.0 Fogging characteristics (glossiness retention) [%] 9795 92 89 84 98

TABLE 3 Comparative Example 7 Example 8 Example 9 Example 1 CompositionBase vinyl chloride resin⁽¹⁾ 100.0 100.0 100.0 100.0 (parts by mass)Trimellitate plasticizer⁽²⁾ 50.0 30.0 110.0 130.0 1,9-Nonanediol diesterplasticizer 80.0 100.0 — — 1,3-Propanediol diester plasticizer⁽¹⁰⁾ — —20.0 — Epoxidized soybean oil⁽³⁾ 5.0 5.0 5.0 5.0 Perchloric acid-treatedhydrotalcite⁽⁴⁾ 5.0 5.0 5.0 5.0 Zeolite⁽⁵⁾ 1.0 1.0 1.0 1.0Stearoylbenzoylmethane (β-diketone)⁽⁶⁾ 0.3 0.3 0.3 0.3 Zinc stearate⁽⁷⁾0.2 0.2 0.2 0.2 Vinyl chloride resin fine particles 20.0 20.0 20.0 20.0(dusting agent)⁽⁸⁾ Pigment⁽⁹⁾ 4.0 4.0 4.0 4.0 Tensile stress (initial)@23° C. [MPa] 7.9 7.3 9.2 9.2 Tensile elongation (initial) @23° C. [%]370 350 360 360 Viscoelasticity test (peak top temperature) [° C.] −48.8−51.0 −54.8 −46.9

TABLE 4 Comparative Example 10 Example 11 Example 2 Composition Basevinyl chloride resin⁽¹⁾ 100.0 100.0 100.0 (parts by mass) Trimellitateplasticizer⁽²⁾ 110.0 110.0 130.0 3-Methyl-1,5-petanediol diesterplasticizer 20.0 — — 1,6-Hexanediol diester plasticizer — 20.0 —Epoxidized soybean oil⁽³⁾ 5.0 5.0 5.0 Perchloric acid-treatedhydrotalcite⁽⁴⁾ 5.0 5.0 5.0 Zeolite⁽⁵⁾ 1.0 1.0 1.0Stearoylbenzoylmethane (β-diketone)⁽⁶⁾ 0.3 0.3 0.3 Zinc stearate⁽⁷⁾ 0.20.2 0.2 Vinyl chloride resin fine particles 20.0 20.0 20.0 (dustingagent)⁽⁸⁾ Pigment⁽⁹⁾ 4.0 4.0 4.0 Tensile stress (initial) @23° C. [MPa]8.8 8.8 9.2 Tensile stress (initial) @−35° C. [MPa] 19.2 19.2 21.0Tensile elongation (initial) @23° C. [%] 360 370 360 Tensile elongation(initial) @−35° C. [%] 210 220 200 Tensile stress (after 250 hoursheating) @23° C. [MPa] 16.6 15.2 13.6 Tensile stress (after 250 hoursheating) @−35° C. [MPa] 30.0 29.2 28.6 Tensile elongation (after 250hours heating) @23° C. [%] 330 310 310 Tensile elongation (after 250hours heating) @−35° C. [%] 100 120 120 Viscoelasticity test (peak toptemperature) [° C.] −52.9 −52.9 −46.9 Embrittlement temperature [° C.]−55.0 −54.0 −49.0 ⁽¹⁾ZEST 2500Z (vinyl chloride resin particles, averagedegree of polymerization 2,500, average particle diameter 130 μm)produced by Shin Dai-ichi Vinyl Corporation ⁽²⁾TRIMEX N-08 produced byKao Corporation ⁽³⁾ADK CIZER O-130S produced by ADEKA Corporation⁽⁴⁾ALCAMIZER 5 produced by Kyowa Chemical Industry Co., Ltd.⁽⁵⁾MIZUKALIZER DS produced by Mizusawa Industrial Chemicals, Ltd.⁽⁶⁾Karenz DK-1 produced by Showa Denko K.K ⁽⁷⁾SAKAI SZ2000 produced bySakai Chemical Industry Co., Ltd. ⁽⁸⁾ZEST PQLTX (vinyl chloride resinfine particles, average degree of polymerization 800, average particlediameter 2 μm) produced by Shin Dai-ichi Vinyl Corporation ⁽⁹⁾DA PX-1720Black (A) produced by Dainichiseika Color and Chemicals Mfg. Co., Ltd⁽¹⁰⁾SALACOS PR-85 produced by Nisshin OilliO Group, Ltd.

Molded products (vinyl chloride resin molded sheets) obtained throughpowder slush molding of the vinyl chloride resin compositions inExamples 2-6 had low loss modulus peak top temperatures and lowembrittlement temperatures, and thus had superior flexibility at lowtemperatures. These molded products also had superior initial tensilecharacteristics at both normal and low temperatures.

Molded products (vinyl chloride resin molded sheets) obtained throughpowder slush molding of the vinyl chloride resin compositions inExamples 7-9 had low loss modulus peak top temperatures and thus hadsuperior flexibility at low temperatures. These molded products also hadsuperior initial tensile characteristics at normal temperature.

Molded products (vinyl chloride resin molded sheets) obtained throughpowder slush molding of the vinyl chloride resin compositions inExamples 10 and 11 had low loss modulus peak top temperatures and lowembrittlement temperatures, and thus had superior flexibility at lowtemperatures. These molded products also had superior initial andpost-heating tensile characteristics at both normal and lowtemperatures.

Among these examples, Examples 2-4 in particular are examples of vinylchloride resin compositions that provide molded products withparticularly superior glossiness retention and flexibility at lowtemperatures that is superior to that provided by a conventionaltechnique (Comparative Example 1).

Molded products obtained through powder slush molding of the vinylchloride resin compositions in Comparative Examples 1 and 2, which didnot include a diester plasticizer, had similar tensile characteristicsto the molded products in Examples 2-11, but had high loss modulus peaktop temperatures and high embrittlement temperatures, and thus had poorflexibility at low temperatures.

INDUSTRIAL APPLICABILITY

The presently disclosed vinyl chloride resin composition is highlysuitable as, for example, a molding material for a surface skin of anautomobile interior material such as an instrument panel or a door trim.

The invention claimed is:
 1. A vinyl chloride resin compositioncomprising: (a) a vinyl chloride resin; (b) a diester plasticizer formedfrom a compound represented by formula (1) shown below

where R¹ and R³ are monovalent hydrocarbon groups having a carbon numberof at least 4 and no greater than 9 that may be the same or differentand R² is a divalent hydrocarbon group having a carbon number of atleast 6 and no greater than 14; and (c) a trimellitate plasticizer,wherein a blending ratio of (b) the diester plasticizer relative to (c)the trimellitate plasticizer, expressed as a mass ratio, is from 20/110to 60/70, (a) the vinyl chloride resin includes (x) vinyl chloride resinparticles having an average particle diameter of at least 50 μm and nogreater than 250 μm in an amount of from 70 mass % to 100 mass % and (y)vinyl chloride resin fine particles having an average particle diameterof at least 0.1 μm and no greater than 10 μm in an amount of from 0 mass% to 30 mass %, and wherein R² in formula (1) has a straight chain ratioof at least 90 mol %, where the straight chain ratio is a proportion ofstraight chain hydrocarbon groups relative to all hydrocarbon groups inR², and wherein a vinyl chloride resin molded product obtained throughpowder molding of the vinyl chloride resin composition has a peak toptemperature of a viscoelasticity test of from −54.8° C. to −52.7° C. 2.The vinyl chloride resin composition of claim 1, wherein an amount of(b) the diester plasticizer is from 5 parts by mass to 200 parts by massrelative to 100 parts by mass of (a) the vinyl chloride resin.
 3. Thevinyl chloride resin composition of claim 1, wherein a total amount of(b) the diester plasticizer and (c) the trimellitate plasticizer is from5 parts by mass to 200 parts by mass relative to 100 parts by mass of(a) the vinyl chloride resin.
 4. The vinyl chloride resin composition ofclaim 1, wherein R¹ and R³ in formula (1) are monovalent aliphatichydrocarbon groups having a carbon number of at least 4 and no greaterthan 9 that may be the same or different, and R² in formula (1) is adivalent aliphatic hydrocarbon group having a carbon number of at least6 and no greater than
 14. 5. The vinyl chloride resin composition ofclaim 1, wherein R¹ and R³ in formula (1) each have a straight chainratio of at least 90 mol %, where the straight chain ratios of R¹ and R³are proportions of straight chain hydrocarbon groups relative to allhydrocarbon groups in R¹ and R³, respectively.
 6. The vinyl chlorideresin composition of claim 1 used in powder molding.
 7. The vinylchloride resin composition of claim 1 used in powder slush molding.
 8. Avinyl chloride resin molded product obtained through powder molding ofthe vinyl chloride resin composition of claim 1, wherein the vinylchloride resin molded product is used as a surface skin of an automobileinstrument panel.
 9. A laminate comprising: a foamed polyurethane moldedproduct; and a vinyl chloride resin molded product obtained throughpowder molding of the vinyl chloride resin composition of claim 1.